I was able to walk through blocks at head height with elytra equipped. Solid blocks, stairs, slabs, fences, trapdoors, bedrock, and even barriers. It appears that the top half of the player's hitbox is broken. Steve will only walk through the block if there is no block below it, otherwise, it works as intended and steve is unable to phase through walls. 

I was unable to recreate this and provide screenshots. The camera behaves glitchy, unlike when the player suffocates.